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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c277a0 of 8 bytes by task 11806 on cpu 0:
 bh_lru_install fs/buffer.c:1242 [inline]
 find_get_block_common+0x459/0x870 fs/buffer.c:1307
 bdev_getblk+0x4d/0x3f0 include/linux/gfp.h:-1
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 __ext4_get_inode_loc+0x303/0x930 fs/ext4/inode.c:4890
 ext4_get_inode_loc fs/ext4/inode.c:5018 [inline]
 ext4_reserve_inode_write+0xd7/0x250 fs/ext4/inode.c:6372
 __ext4_mark_inode_dirty+0x8c/0x3d0 fs/ext4/inode.c:6550
 ext4_dirty_inode+0x92/0xc0 fs/ext4/inode.c:6587
 __mark_inode_dirty+0x16f/0x710 fs/fs-writeback.c:2623
 generic_update_time fs/inode.c:2198 [inline]
 touch_atime+0x21d/0x330 fs/inode.c:2273
 file_accessed include/linux/fs.h:2264 [inline]
 ext4_file_mmap_prepare+0x13a/0x1a0 fs/ext4/file.c:840
 vfs_mmap_prepare include/linux/fs.h:2076 [inline]
 call_mmap_prepare mm/vma.c:2672 [inline]
 __mmap_region mm/vma.c:2755 [inline]
 mmap_region+0xed6/0x20d0 mm/vma.c:2857
 do_mmap+0x9b2/0xbd0 mm/mmap.c:560
 vm_mmap_pgoff+0x183/0x2d0 mm/util.c:581
 ksys_mmap_pgoff+0x267/0x310 mm/mmap.c:606
 x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c277a0 of 8 bytes by task 8965 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1448
 smp_call_function_many_cond+0x2a7/0xb70 kernel/smp.c:836
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1057
 on_each_cpu_cond include/linux/smp.h:106 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1457
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x94/0x1a0 block/bdev.c:720
 blkdev_put_whole block/bdev.c:727 [inline]
 bdev_release+0x2bf/0x3d0 block/bdev.c:1152
 blkdev_release+0x15/0x20 block/fops.c:705
 __fput+0x29b/0x630 fs/file_table.c:510
 ____fput+0x1c/0x30 fs/file_table.c:538
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x211/0x820 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888100723dd0 -> 0xffff888100504208

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8965 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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